This invention relates to dynamically counterweighted closure system comprising a vertically collapsing segmented door, door roller guide rails promoting the collapse while otherwise guiding door opening and closing and a variable counterweight connected to the operating door to compensate varying dynamic and/or static forces exerted by this load as a known function of its position.
In ordinary overhead closures such as used in residential garage construction, required operating forces are provided by a torsional or extensional spring system as supplemented by an electric motor drive system. Required operating forces are dynamic in nature and do not vary linearly with opening distance. A spring counterweight offers a linearly varying resistance force which is essentially massless and, hence, does not offer most effective counterweighting. Commonly, they now serve as a supplement to an electric motor drive system, the latter being engaged the entire closure opening or closing period. Manual operation is achieved by first disconnecting the motor drive from the door structure and then physically supplementing the energy deficient spring counterweight system. Of course increased door heights and weights complicate application of such closure systems. Spring displacements and forces must significantly increase as well as the electric motor capacity. Differences between the linearly varying spring force and the required non-linear dynamic and/or static operating forces become far more significant. Additionally, in the case of increased door dimensions, there is increased encroachment on valued interior space and further degradation of esthetics.
The object of this invention is to supplement the related reference inventions in providing an industrial as well as residential closure system that minimizes external energy requirements, provides for more flexible closure operating, allows increased design latitude in incorporating energy conservation and architectural options, reduces encroachment upon valuable interior building space and greatly promotes the esthetic value of the enclosed utility space.
The invention minimizes external energy requirements and provides for more flexible closure operation by applying the referenced related inventions. A physical form and operational scheme most appropriate for residential closure construction is featured in this invention. Static and dynamic forces that arise from desired closure operations vary as a known function for every cycle of motion of the door's path. The related inventions allow optimally compensating all such forces that regularly vary in regards to geometry of door position through the use of a counterweight composed of weight components which may be individually arrested during movement of the door at predetermined regular stations. Accordingly, considerable optimal compensation for all static and dynamic operating forces is achieved, whereby the system consisting of load and counterweight at any time is precisely or at least very nearly in equilibrium. This equilibrium also applying to the dynamic forces (accelerations), no appreciable external force is required to initiate or arrest door motion. The kinetic and/or potential energies being generated are entirely recovered within the system, and the supply of external energy is restricted to making good the losses arising from friction, air resistance, etc. The external energy requirement is satisfied by electric power either between the closure opening and closing periods or during one of the latter periods. Accordingly, the electric power can be applied at the desired rate of door operation to affect either opening or closing with the return in both cases being achieved strictly under the influence of the counterweights only. Alternately, both opening and closing may be achieved under the influence of the counterweights only with the electric power being applied between these two motion stages at any desired rate, the lower rates requiring reduced external electric power levels. However, the operation of the closure is never exclusively dependent on the electric power. At the option of the operator, the closure may be exercised manually with the required minimized external energy being applied manually during the opening or closing of the door. As a consequence of such dynamic counterweighting tailored according to operating demands, there is less significance of door weight increases that may be necessary to accommodate certain architectural or energy conservation measures. The latter do not result in operating or initial electric motor purchase costs penalties. The counterweight system allows moving very heavy and large doors in short time periods, without requiring large power machinery. In all cases, required output is restricted to that energy which will replenish the looses within the available time, with the available time generally exceeding the operating time when the option is exercised to apply the minimum required external energy during operational pauses, so that very low power suffices to this end.
The invention significantly reduces encroachment upon valuable interior building space through the use of a segmented door that collapses vertically during the opening stage. When the door is in an opened position, occupied useable space is limited in overhead cabinet roughly equal in dimensions to the width of the door, the height of one door segment and the combined thickness of the door segments. Door roller guide rails are compactly positioned vertically along the door casing into the overhead cabinet with mounting onto its end panels. Since the door sections only begin to collapse at the upper level of the opening, door operations do not encroach on any useable space other than that required by the overhead storage cabinet. The counterweight system and connecting cables may be compactly placed within the wall cavity, usually consisting of stud/sheathing construction. The overhead ceiling area usually reserved for an overhead door in its opened horizontal configuration is not required and may be used for other building utility systems such as lighting or ducting or otherwise unencroached upon. Accordingly, the invention also greatly promotes the esthetic value of the enclosed space. Architectural attractiveness is not limited to the exterior alone as currently is common practice. There are no unsightly interior features. More positively, the invention provides a closure system that is most adaptable to attractive interior design. For example, the appearance of a residential garage may now be made compatible with the many various functions they now serve in addition to that of vehicle storage. Increased space utilization may be exploited. Certainly, the residential garage potentially offers far more complete versatility in meeting changing family demands for effective dual use interior home area than is now possible with today's unattractive energy inefficient garage door systems.
A preferred embodiment of the dynamically counterweighted closure system of the invention comprises a vertically collapsing segmented panel door; adjoining vertical roller guide rails cam equipped in certain cases, to promote controlled vertical door motion and panel collapse and an adaptation of the counterweight systems of the referenced inventions comprising several partial weights in the counterweight, which are detachably connected to the door load, further devices which separate individual partial weights from the door load at predetermined points of the path of the counterweight and additional devices which apply external energy to the counterweight system by inducing relative displacement between certain of the partial weights.